Process of coating and treating materials having an iron base



J. L. HERMAN.

PROCESS OF COATING AND TREATING MATERIALS HAVING AN IRON BASE.

I ,43Ufi5fl. Patented Oct. 3,1922

HEAT- TREATER COAT/N6 BATH AND ANNE LEE DRIER Patented ct. 3, ll

JOSEPH L. HERMAN, 01E PEOBIA, ILLINOIS.

4 PROCESS OF GOATING AND TREATING MATERIALS HAVING AN IRON BASE.

Application filed March 6, 1922. Serial No. 541,562.

T 0 all whom it may concern: I

Be it known that I, JOSEPH L. HERMAN, a citizen of the United States, aresident of Peoria, in the county of Peoria and State of Illinois, haveinvented new and useful Improvements in Processes of Coating andTreating Materials Having an Iron Base, of which the following is aspecification.

This invention has reference to a process of coating and treatingmaterials having an iron base and particularly the coating and treatmentof wire used in the fence industry and for telephone and other purposes.

The principal object of the invention is to subject the material to asimultaneous annealing and coating process and subsequentlyheat-treating the coating. Such heat-treatment has for its object animproved coating which will be more resistant to atmospheric, rustingand corroding conditions than is ordinary galvanized Wire, and whichfurther will permit a heavier coated wire to be used in wire fabricatingmachines Without causing the coating to crack or flake off as is thecasewith heavily coated galvanized Wire coated by ordinary processes; theannealing of the material being for the usual softening purposes.

A further object of the invention is to permit the use of higher speedsfor galvanizing wire than can be used under the ordinary galvanizingprocesses where heavier coatings are desired and at the same timecausing a heavier coating to be formed on the wire.

This application is a companion lA) applications for patent filed by meof even date herewith bearing Serial Nos. M1561 and 541,563 and theapplication for patent filed by me on February 10, 1922 hearing SerialNumber 535,660, all directed towards processes for coating and treatingmaterials having an iron base. The invention herein described difi'ersfrom those disclosed in said companion applications, in that theannealing of the material takes place simul taneously with the coatingthereof.

Galvanized wire which is to be used for fabricating purposes and moreparticularly that which is to be used in the manufacture of woven wirefencing must have a relatively heavy coating of spelter in order to beable to withstand atmospheric corroding conditions, and before myinvention was developed this was not possible except at a much increasedcost of production.

The universal practice for testing the relative value of spelter ongalvanized wire is by the so-called Preece or copper sulfate test. Thereare other tests, however, which are used for quantitatively determiningthe amount of spelter on galvanized wire, such as stripping the coatingin caustic soda solution; in a suitable hydrochloric acid solution; in asolution of hydrochloric acid and 6 antimony chloride, and in a leadacetate solution. The copper sulfate test, although not strictlyquantitative, is comparative when used under known conditions oftemperature and strength, and being a quick test, and one which can beperformed by any one after a. little experience, has come to be ,theroutine testin medium for 'alvanizcd wire coatings.

At the present time there are only two ('2) methods in use whereby thesenecessary heavy zinc (spelter) coatings may be obtained by the hotprocess of galvanizing. The first method is to pass the wire very slowlyas it emerges from the galvanizing bath, through finely dividedcharcoal. By such a process a smooth, thick coating may be obtained.This method is used for making telephone wire. It has serious drawbacks,however, from' an economic standspelter, the speed depending on thegauge of wire, the thickness of coating desired and the length of themolten spelter bath, and then wiping the wire by passing it he tweensuitable wipers. In other words, a

wire will have a heavier galvanized coating,

as measured by the copper sulfate test. the longer it remains in themolten spelter. This latter process, too. has its econom c drawbacks,because of the slow speeds re quired, the long spelter pans necessaryand consequently the lessening of the tonnage passing through agalvanlzing unit in agiven time.

without 90 In the accompanyin drawing there is illustrateddiagrammatically the usual or ordinary continuous galvanizing or coatingapparatus, except the annealing furnace, which is not placed as it isordinarily, and includes the acid bath, flux bath, coating orgalvanizing bath and my heattreater associated therewith, butin thisinstance my coating bath is used as a combined coating bath andannealer.

I have discovered that if the, material is subjected to a molten coatingbath the temperature of which is high enough to cause annealing, Iobtain a heavily coated material and at the same time eliminate theusual annealing furnace. If this-material then subjected to aheat-treatment such as I have disclosed in said copending applicationbearing Serial Number 535,660, I have acoated product superior to thatwhich can be obtained by ordinary galvanizing processes.

I realize that annealing per se is not new and also realize that coatingis not new, but the process by which I perform these operations andwhich I have described is new, and result in producing a coated wiresuperior to any which can be produced by ordinary coating processesexcept in the case of heavy wires and where long spelter pans areutilized and where relatively slow speeds are used.

I also realize that the annealing temperature will vary for difi'erentcarbon contents, or kinds of wire, or' whether the annealing is torelieve the strain of bench hardening that comes from the coldworking'of the wire, or whether from some other source, as I have statedin my companion application bearing Serial Number 541,561. By an--nealing I refer to softening and by heattreatment I have reference tosuch treatment as will produce a physical or chemical change of thematerial undergoing treatment, such as I have disclosed in my copendingapplication bearing Serial Number 535,660.

For example, I have taken a bench hardened 0.12% carbon No. 12 gaugewire and passed it through molten spelter held at a temperature ofapproximately 1250 F. for a period of approximately eight seconds andthen passed the coated wire through a tube heated to about 1250 F. for aperiod of about eight seconds and I then have an annealed product whichnot only has a smooth even pliable coating, but it will also standapproximately four or more one minute immersions in copper sulfate.

I have discovered that by coating material in a spelter bath held atelevated temperatures which are suitable for annealing, I obtain afirmer bonding between the coating and the material than is thecaselwith material galvanized by ordinaryprocesses.

In my companion application bearing Serial Number 535,660 I havedisclosed the heat-treating of coated materials having an iron base,such for instance as coated wire, after the coating st'ep,and ofmaterial which is annealed in any well known manner prior to the coatingthereof. In this application I claim a simultaneous annealing andcoating of material in a coating bath maintained at a temperature highenough to anneal, atisay about 1300 degrees F. I have found in thecoating of fence wire that I get very good results by simultaneouslyannealing and coating larger wire of gauges such as No. 9, and create aneffective bonding action between the coating and the base material;however, such bonding action'is not as effective in the case of smallergauge-s of wire, such as No, 14, because the small body does not retaina sufficient amount of heat to be as effective as the larger bodies andtherefore the subsequent heat-treatment is desirable and is employed forthe purpose of'accomplishing similar results as that disclosed by theuse of the heat-treater in my companion application bearing SerialNumber 535,660.

I do not wish to limit myself to the temperatures and periods of timegiven above as I have clearly stated and shown in my copendingapplication bearing Serial Number 535.660 that times, speeds and gaugesof wire may be utilizedin'a multitude of combinations without departingfrom the spirit and scope of the invention.

What I claim is 1. The process of galvanizing wire, which consists incontinuously moving the wire and. during such movement subjecting thewire to a simultaneous annealing and metallic coating action.

2. The process of galvanizing wire, which consists in continuouslymoving the Wire and during such movement subjecting the same, first to asimultaneous annealing and metallic coating action and thenheat-treating said coated and annealed wire.

3. The process of treating un-annealed materials having an iron basewhich consists in subjecting such material to a simultaneous annealingand metallic coating action.

4:. The process of treating un-annealed materials having an iron basewhich consists in subjecting the same, first to a simultaneous annealingand metallic coating action and then heat-treating said coated andannealed material.

' In witness whereof, I have hereunto afiixed my hand and seal this 4thday of March,

JOSEPH L. HERMAN.

